PT-2024-33713 · Linux+7 · Linux Kernel+7
Syzbot
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Published
2024-09-28
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Updated
2025-05-28
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CVE-2024-49868
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions:
Linux kernel versions prior to 6.6.58
Description:
A NULL pointer dereference vulnerability has been resolved in the Linux kernel. The issue occurs when a new transaction fails to start, leading to a NULL pointer dereference in the
btrfs update reloc root() function. This happens because the fs info->reloc ctl is set to NULL during error handling, but the code still attempts to access its merge reloc tree stage. The vulnerability is caused by a race condition between the set reloc control() and unset reloc control() functions, which can result in a reloc root being created for a subvolume during the error path cleanup.The estimated number of potentially affected devices is not provided. There is no information about real-world incidents where this issue was exploited.
Technical details about exploitation include:
- The vulnerable function is
btrfs update reloc root(). - The vulnerable variable is
fs info->reloc ctl. - The
start transaction()function insideprepare to relocate()can fail, leading to the NULL pointer dereference. - The
btrfs commit transaction()function is also involved in the exploitation path.
Recommendations:
For Linux kernel versions prior to 6.6.58, update to version 6.6.58 or later to resolve the issue. As a temporary workaround, consider disabling the
btrfs update reloc root() function until a patch is available. However, this is not a recommended solution and may have unintended consequences. The best course of action is to update to a patched version of the Linux kernel.Exploit
Fix
NULL Pointer Dereference
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Astra Linux
Debian
Linuxmint
Linux Kernel
Red Os
Suse
Ubuntu